Question

UIButton setBackgroundImage和setImage方法的区别

Answer 1

区别如下：
1，setBackgroundImage，图片会随着按钮的大小而改变，图片自动会拉伸来适应按钮的大小，这个时候任然可以设置按钮的title，图片不会挡住title；
2，setImage，此时再设置title，title将无法显示。图片不会随着按钮的大小改变而改变。
代码说明下，使用的图片的大小是70＊27：
UIButton *btn2 = [UIButton buttonWithType:UIButtonTypeCustom];
[btn2 setBackgroundImage:[UIImage imageNamed:@"sign.png"] forState:UIControlStateNormal];
[btn2 setTitle:@"AAA" forState:UIControlStateNormal];
btn2.frame = CGRectMake( 10 , 200, 75, 27 );
[self.view addSubview:btn2 ];1234512345

采用setImage：
UIButton *btn2 = [UIButton buttonWithType:UIButtonTypeCustom];
[btn2 setImage:[UIImage imageNamed:@"sign.png"] forState:UIControlStateNormal];
[btn2 setTitle:@"AAA" forState:UIControlStateNormal];
btn2.frame = CGRectMake( 10 , 200, 75, 27 );
[self.view addSubview:btn2 ];```

123456789123456789

把按钮的大小改变，代码如下：

UIButton *btn2 = [UIButton buttonWithType:UIButtonTypeCustom];

[btn2 setBackgroundImage:[UIImage imageNamed:@”sign.png”] forState:UIControlStateNormal];

[btn2 setTitle:@”AAA” forState:UIControlStateNormal];

btn2.frame = CGRectMake( 10 , 200, 175, 27 );

[self.view addSubview:btn2 ];

效果如下

采用setImage，代码如下

UIButton *btn2 = [UIButton buttonWithType:UIButtonTypeCustom];

[btn2 setImage:[UIImage imageNamed:@”sign.png”] forState:UIControlStateNormal];

[btn2 setTitle:@”AAA” forState:UIControlStateNormal];

btn2.frame = CGRectMake( 10 , 200, 175, 27 );

[self.view addSubview:btn2 ];
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